Luminal coupling system

ABSTRACT

A luminal coupling tube system for providing access to a lumen of a subject is disclosed. The system includes an internal magnet assembly, a snare assembly, an external magnet, a pull wire system and a feeding tube assembly. The internal magnet assembly includes an internal magnet having a first coupling surface and a tether for traversing an endoscope instrument channel. The snare assembly includes a snare, a snare operating device, and a cable. The external magnet includes a second coupling surface. The polar orientation of the external magnet is opposite the polar orientation of the internal magnet such that the first and second coupling surface are magnetically attracted. The pull wire system includes a needle, a cannula and a pull wire. The feeding tube assembly includes a tube, a snare, a connector, and a dome fixed to the tube. A method of use is disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This PCT patent application claims benefit of U.S. Provisional PatentApplication Ser. No. 60/381,201 entitled “Luminal Coupling System” andfiled with the United States Patent and Trademark Office on May 17,2002.

FIELD OF THE INVENTION

The present invention relates to a luminal coupling system and moreparticularly to a luminal magnetic coupling system for providing accessdirectly to a lumen within a subject.

BACKGROUND OF THE INVENTION

Many different medical protocols require a surgeon to access a lumen, ororgan, with a body. One frequent occurring protocol is the need tosupply nutritional directly to the gastrointestinal tract.

Various techniques for providing nutritional to a subject are inwidespread use in hospitals, nursing homes, and other medicalfacilities. Most techniques include either feeding the subjectintravenously or directly into the gastrointestinal tract through themouth. Protocol for certain medical conditions calls for feedingdirectly into the gastrointestinal tract, rather than into a vein. Mostof these conditions involve inserting a tube through the nose or mouthinto the esophagus. However, certain known techniques are not availablein specific cases due to a surgically altered anatomy, a gastric outletobstruction, or an increased risk of gastro-respiratory reflux. Theseand certain other conditions require direct jejunal feeding.

Conventional jejunal feeding methods include a naso-jejunal tube, asurgical jejunostomy, interventional radiologic jejunostomy and directpercutaneous endoscopic jejunal system. The naso-jejunal tube isuncomfortable, visually not appealing, and has a tendency to clog. Thesurgical jejunostomy and interventional radiologic jejunostomy can beeffective procedures, but are prohibitively expensive. The directpercutaneous endoscopic jejunal procedure is technically challenging andbeyond the comfortable skill range of many surgeons. Specifically, thelumen, or cavity of the tubular-shaped bowels, is not fixed during theprocedure, making properly inserted without injury or undesirableeffects difficult.

The present invention provides a new and improved luminal magneticcoupling system for providing access directly to a lumen within asubject. The present invention uses magnetically coupling internal andexternal magnets to provide an inexpensive, precise and technicallyachievable system and method.

SUMMARY OF THE INVENTION

In an illustrated embodiment of the invention a luminal magneticcoupling system for providing access directly to a lumen within asubject is provided. The luminal magnetic coupling system includes aninternal magnet assembly, a snare assembly, an external magnet, a pullwire system and a feeding tube assembly.

The internal magnet assembly is inserted into an endoscope instrumentchannel. The internal magnet assembly includes an internal magnet and atether. The internal magnet includes a first coupling surface defining asurface shape and size. The internal magnet is characterized by a polarorientation and a magnetic strength. The tether includes a first endportion fixed to the magnet, a second end portion disposed remote fromthe first end portion, and a middle portion spaced between the first andsecond end portions. The middle portion traversing the endoscopeinstrument channel.

The snare assembly includes a snare, a snare operating device, and acable connecting the snare to the snare operating device.

The external magnet includes a second coupling surface defining asurface shape and size. The external magnet is characterized by a polarorientation and a magnetic strength. The polar orientation of theexternal magnet is opposite the polar orientation of the internal magnetsuch that the first and second coupling surfaces are magneticallyattracted to each other.

The pull wire system includes a needle, a cannula and a pull wire. Thepull wire comprises a mating end and a pull end.

The feeding tube assembly includes a tube having a first end and asecond end, a snare, a connector fixedly joining the tube first end tothe snare, and a dome fixed to the tube second end.

The dome may include a bottom surface having a tube mounting hole and anannular-shaped perforated side surface. The perforated side surface isdesigned to distribute liquid in a plurality of radial directions.

The magnetic strength of the internal magnet and the magnetic strengthof the external magnet may be collectively sufficient to magneticallycouple the internal and external magnets when juxtaposed of either sideof an lumen wall.

The magnetic strength of the internal magnet and the magnetic strengthof the external magnet may be of collectively sufficient strength tostabilize an intestinal lumen to an abdominal wall when the magnets arejuxtaposed of either side of an abdominal wall.

The surface shape and size of the first coupling surface and the surfaceshape and size of the second coupling surface may be essentially thesame.

The external magnet may comprise structure defining a needle insertionzone. The internal magnet may comprise structure defining a needleacceptance zone. The needle insertion zone and the needle acceptancezone may cooperatively align when the external magnet and the internalmagnet are magnetically coupled.

The present invention offers advantages over devices available in theprior art. The system is inexpensive and easy to use. Patient recovertime and risk of infection is reduced over certain prior art systems andmethods.

Further features and advantages of the invention will become apparentfrom the following detailed description made with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1H are a series of schematic views of a prior art system usedto insert a feeding tube directly into the small intestine of a subject;

FIG. 2 is a perspective view of a part of a system constructed inaccordance with a preferred embodiment of the present invention, showingan internal magnet assembly;

FIG. 3 is a top view of the internal magnet illustrated in FIG. 2;

FIG. 4 is a perspective view of several parts of a system of the presentinvention, showing the internal magnet assembly magnetically coupled to,and cooperatively aligned with, an external magnet to advantageouslyallow needle insertion through each magnet;

FIG. 5 a is a perspective view of an alternative design of the partsillustrated in FIG. 4, showing an alternative design of a needleinsertion zone and a needle acceptance zone;

FIG. 5 b is a perspective view of an alternative design of the partsillustrated in FIG. 4, showing the design of a needle insertion zone anda needle acceptance zone illustrated in FIG. 5 a;

FIG. 6 is a perspective view of a part of a system of the presentinvention, showing a feed tube assembly;

FIG. 7 is a perspective view of a part of a system of the presentinvention, showing a external magnet and a sleeve;

FIG. 8 is a perspective view of a part of a system of the presentinvention, showing a lock;

FIG. 9 a is a perspective view of a part of a system of the presentinvention installed in an endoscope instrument channel, showing a snareassembly and an internal magnet assembly at the proximal end of theendoscope with respect to the user;

FIG. 9 b is a perspective view of a part of a system of the presentinvention installed in an endoscope instrument channel, showing a snareassembly and an internal magnet assembly at the distal end of theendoscope with respect to the user;

FIG. 10 is a perspective view of a part of a system of the presentinvention, showing a pull wire;

FIGS. 11 a-11 d are top views of alternative designs of a part of asystem of the present invention, showing external magnets having varyingneedle insertion zones; and

FIG. 12 is a perspective view of several parts of a system of thepresent invention, showing the internal magnet of FIG. 1 d.

BEST MODE CONTEMPLATED FOR CARRYING OUT THE INVENTION

A luminal magnetic coupling system for providing access directly to alumen is disclosed. The system may be used for any medical procedurethat requires access to a lumen within a subject. For exemplary purposesonly, the system will be described for use in an endoscopic feeding tubeinstallation into the small intestines. In this example, the system isconstructed and arranged so that a surgeon can easily and confidentlyperform a direct percutaneous endoscopic jejunal feeding tubeinstallation.

The system is designed for use with any suitable or conventionalendoscopic surgical equipment. For purposes of this description, thesystem is described in the context of use with an optical endoscopicapparatus. A suitable endoscope will have an elongated body and aninstrument channel. Surgical instruments, such as portions of the systemconstructed in accordance with the present invention, may be introducedthrough an instrument channel, which extends axially throughout the bodyof the scope. In addition, the scope may have optical and illuminationfeatures that are used by the surgeon during the practice of thisinvention.

The system contains several specific advantages over known prior arttechniques, including the technique illustrated in FIGS. 1 a-1 h. Asseen in FIG. 1 a, the prior art technique relies upon the imprecisetransillumination of the endoscope 205 to determine a needle insertionpoint 210 in a subject 200. The present invention uses a magnet systemto determine a desired location within the intestine for installing afeeding tube. Further, the present invention uses magnets featuring aneedle insertion zone and a needle acceptance zone for determining aprecise insertion point for a sounding needle.

Referring now to the FIGS. 2-6, 9 b and 10, the system includes aninternal magnet assembly 20, a snare assembly 30, an external magnet 40,a pull wire system 120 and a feeding tube assembly 60.

Referring first to FIG. 2, the internal magnet assembly 20 includes aninternal magnet 25 and a tether 27. The internal magnet includes a firstcoupling surface 28 defining a surface shape and size. The internalmagnet 25 is characterized by a polar orientation and a magneticstrength. The tether 27 includes a first end portion 27 a fixed to themagnet 25 and a second end portion 27 c (not shown) disposed remote fromthe first end portion, and a middle portion 27 b spaced between thefirst and second end portions. The middle portion 27 b traversing theendoscope instrument channel when installed.

The magnet 25 may be fixed to the tether in any conventional manner. Asillustrated in FIG. 2, the tether end portion 27 a is inserted through amounting hole 29 in the magnet. FIG. 3 shows a possible location of amounting hole when viewing the magnet from the top. As shown, themounting hole is located a distance D₁ from the center point of themagnet. In one embodiment, the distance D₁ is less then half of thedistance D₂, the radius of the magnet. The mounting hole may be formedby a laser drilling technique.

Any suitable magnet may be used in the practice of this invention. Apreferred magnet is constructed from one or more rare earth metals. Onepreferred magnet is constructed of Neodymium Iron Boron (NdFeB). In analternative design of the present invention, only one of either theinternal disk or external disk are actually magnetic, while the otherdisk is merely iron.

Any suitable magnet size providing a sufficient field of concentrationmay be used in the practice of this invention. However, it is believedthe ability to successfully perform the present invention is increasedwith decreasing magnet size. An internal magnet of the preferredembodiment has a width not greater than 1 inch. The preferred magnet isabout 0.75 inches in diameter. Although not wanting to be bound bytheory, it is believe a magnet of this reduced size provides a magneticfield of increased concentration over a smaller surface area. Thisadvantageously permits internal and external magnet alignment, anddecreases the risk of improper needle insertion. A magnet for thepractice of this invention is commercially available from EdmundIndustrial Optics, at fax number (856) 573-6295. This exemplary magnethas a strength of 11.0 lbs. lift.

Referring now to FIG. 4, a perspective view of several parts of a systemof the present invention is shown. Specifically, an internal magnet 25is shown magnetically coupled to, and cooperatively aligned with, anexternal magnet 40. The structure of the internal magnet 25 and theinternal magnet 40 advantageously allow a needle 110 to be insertedthrough the magnets 25, 40. Specifically, the needle is inserted througha needle insertion zone define by a void 41 in the external magnet 40and an needle acceptance zone define by a void 26 in the internal magnet26.

In the preferred embodiment, the internal magnet is coated with abiocompatible material. This coating advantageously prevents the magnetfrom reacting with the corrosive environment of the gastrointestinaltract, preventing undesired reaction by-products from entering thesubject. The coating may be silicon or any other suitable coating knownto one with ordinary skill in the art.

As illustrated, the lumen 80, i.e., duct wall of a tubular organ, isstabilized against a portion of the abdominal wall 85 disposed at theinternal target location. The improvement of the stabilizing of thelumen 80 advantageously permits ease of certain method steps of thepresent invention.

As illustrated, external magnet 40 includes a second coupling surface 45defining a surface shape and size. The external magnet is characterizedby a polar orientation and a magnetic strength. The polar orientation ofthe external magnet is opposite the polar orientation of the internalmagnet such that the first and second coupling surfaces 28, 45 aremagnetically attracted to each other.

Referring to FIG. 5 a, a perspective view of an alternative design ofthe parts illustrated in FIG. 4 is shown. The alternative designfeatures a different needle insertion zone 52 a and needle acceptancezone 52 b. FIG. 5 b is a perspective view of a design featuring theneedle insertion zone and a needle acceptance zone illustrated in FIG. 5a.

As illustrated in FIGS. 5A and 5B, the first coupling surface 28 andsecond coupling surface 45 have essentially the same shape and size.This allows for advantageous magnet aligning and precise needleinsertion. As illustrated in FIGS. 11 a-11 d, external magnets 140, 141,142, 143 of various structure are shown in top views. FIG. 11 d asillustrated is an oblong-shaped ellipsoid having a top planar secondcoupling surface 28. Various needle insertion zones 100, 101, 102, 103are illustrated in the top views provided. Any suitable needle insertionpoint within the zone may be chosen. Further, each magnet design may beused with one or more needle insertion zone design.

Although not wanted to be bound by theory, it is believe that the magnetshape shown in FIG. 11 d will offer the least resistance as it istransported down the lumen tract, as well as having beneficial safetyfeatures. Referring now to FIG. 12, a perspective view of the internalmagnet of FIG. 1 d is shown in use within a subject. The internal magnet225 is an oblong-shaped ellipsoid. This beneficial structure achieves atunneling effect when transported within a lumen of a subject such thatother tissue and organs are pushed distally away from the magnet. Thisnegates a concern that any non-targeted organs could get positioned onor above the internal magnet and get carried up the other anteriorabdominal wall 80 where they could be pierced with the introducer needle110. FIG. 12 illustrates an internal magnet 225 that has pushed aninternal intestine 200 away from the magnet such that no non-targetedtissue or organs are in the insertion path of the needle 110.

An exemplary feeding tube assembly 60 is illustrated in FIG. 6. Thefeeding tube assembly 60 includes a tube 62 having a first end 63 and asecond end 64, a snare 65, a connector 67 fixedly joining the first end63 to the snare 65, and a dome 68 fixed to the tube second end 64. Asshown, the connector 67 is advantageously cone-shaped to permitlow-resistance travel through the lumen during installation of thefeeding tube. The snare 65 may be used to attach to the mating end 122of the pull wire 120 illustrated in FIG. 10.

The dome 68 includes a bottom surface having a tube mounting hole and anannular-shaped side surface including perforations 69. Once properlyinstalled within a subject, the perforation advantageously distributeliquid in a plurality of radial directions.

Referring again to the external magnet 40, in order to increase magnetstrength without increasing the surface area of the second couplingsurface, a stack of external magnets may be used as illustrated in FIG.7. In FIG. 7, a stack of magnets is illustrated within a protectivedisposable sleeve 90. In the practice of the invention, the stack may bean assembly of magnets, with the assembly having a fixed stack height.Alternatively, the stack may include removably joined magnets of equaldiameter. Depending on several factors, e.g., the obesity of thesubject, the stack may be increased or decreased in height, andconsequently, magnetic strength. Use of the sleeve 90 prevents bodilyfluids from contacting one or more external magnets, allowing the stackto be reused.

A perspective view of a part of a system of the present inventioninstalled in an endoscope instrument channel in shown in FIGS. 9 a-9 b.A snare assembly 30 and an internal magnet assembly 20 are shown at theproximal end of the endoscope with respect to the user. The snare cable134 and the tether second end portion 27 c are shown. A companionperspective view of the distal end of the system is shown FIG. 9 b.Specifically, the snare 130 and the internal magnet 25 and the tethermiddle portion 27 b and first end portion 27 a are shown.

Method of Use

A method of the present invention will now be discussed. Dependent uponthe medical condition of the subject, the surgeon must first determineinto which portion of the gastrointestinal tract he or she wishes toinstall the feeding tube. For exemplary purposes, a discussion of themethod of the present invention will focus on installing the tube intothe jejunal region of the small intestines. It should be understood byothers with ordinary skill in the art that the present invention couldbe utilized in other locations within the gastrointestinal tract.

The method may begin with the subject under conscious sedation. Theinternal magnet assembly is inserted into the instrument channel of theendoscope. This can be done by several methods, including entering thetether into the distal end of the device until the internal magnet isdisposed proximal to the distal end of the scope. In this position, thesecond end portion of the tether is disposed remote from the proximalend of the endoscope.

In the preferred embodiment, a lock is installed on the second endportion of the tether. The lock prohibits the internal magnet frommoving relative to a distal end of an endoscope. Although the internalmagnet can be rotated with respect to the scope, or moved slightlycloser to the endoscope, it cannot move a greater distance away from theendoscope. By prohibiting the internal magnet from moving, the surgeonis afforded increased control. The lock may be any known lock type,including a bull dog clamp or a cord lock. A suitable cord lock, modelnumber L105-6MM, is commercially available from A+ Products, Inc, attelephone number (718) 272-8544. A lock 70 is illustrated in FIG. 8.

After the internal magnet assembly 20 is installed, the snare assembly30 may be installed in the same, or a parallel, instrument channel.Alternatively, the snare assembly 30 is installed later in the method.Loading the snare assembly after intubation is actually preferredbecause additional instruments in the instrument channel can causestiffness in the scope and reduce flexibility of the elongated scopeinsertion section. Incidentally, the tether 27 of the magnet assemblyhas a minimal effect on the flexibility of the endoscope.

The subject is then intubulated with the endoscope, similar to the priorart technique shown in FIG. 1A. The surgeon advancing the distal end ofthe endoscope until the internal magnet is adjacent to an internaltarget location in the jejunum. The target location is confirmed usingthe optical features of the endoscope.

The surgeon then utilizes the illumination feature of the endoscope, Byactivating the light on the end of the endoscope, an external targetarea on the exterior surface of the abdominal wall is transilluminated.The external target area advantageously aligns with the internal targetlocation.

The surgeon can now focus upon the method steps that utilize the magnetsystem of the present invention. An external magnet is used tomagnetically couple with the internal magnetically couple with theinternal magnet. FIGS. 4 and 5 show an internal magnet 25 coupled to anexternal magnet 40. As illustrated, the lumen 80, i.e., duct wall of atubular organ, is stabilized against a portion of the abdominal wall 85disposed at the internal target location. The improvement of thestabilizing of the lumen 80 advantageously permits ease of other methodsteps.

As illustrated, external magnet 40 includes a second coupling surface 45defining a surface shape and size. The external magnet is characterizedby a polar orientation and a magnetic strength. The polar orientation ofthe external magnet is opposite the polar orientation of the internalmagnet such that the first and second coupling surfaces 28, 45 aremagnetically attracted to each other. In order to increase magnetstrength without increasing the surface area of the second couplingsurface, a stack of external magnets may be used as illustrated in FIG.7. In FIG. 7, a stack of magnets is illustrated within a protectivedisposable sleeve. In the practice of the invention, the stack may be anassembly of magnets, with the assembly having a fixed stack height.Alternatively, the stack may include removably joined magnets of equaldiameter. Depending on several factors, e.g., the obesity of thesubject, the stack may be increased or decreased in height, andconsequently, magnetic strength.

As illustrated, the first coupling surface 28 and second couplingsurface 45 have essentially the same shape and size. This allows foradvantageous magnet aligning. The surgeon then prepares to insert asounding needle into the subject at the external target area. Thepresent invention allows for precise needle insertion at a desirablelocation. The surgeon determines a needle insertion point by observing aneedle insertion zone. The external magnet includes structure defining aneedle insertion zone. As illustrated in FIGS. 11 a-11 c, externalmagnets of various structure are disclosed. Various needle insertionzones 100, 101,102 are illustrated in the top views provided. Anysuitable needle insertion point with in the zone may be chosen. Otheralternative second coupling surface designs are illustrated in FIGS. 4,5 a and 5 b.

In an alternative design of the present invention, only one of theinternal magnet and external magnet are actually magnet, while the otherone is merely iron.

A surgeon applies local anesthesia to the area around the needleinsertion point and punctures the abdomen with a sounding needle 110.The sounding needle 10 is used to provide a small puncture into thelumen verify proper external location with respect to the desiredinternal location. By using the optical features of the endoscope, thesurgeon then should verifying the sounding needle is properly positionedwithin the gastrointestinal tract. A properly inserted needle piercesonly one wall & the lumen. Any suitable needle may be used in thepractice of this invention. However, an advantageous needle size allowsfor a self heating wound when it is removed. The wound should clot welland present minimal risk of infection.

Once the surgeon verifies the sounding needle is properly located, acannula 112 is inserted adjacent to the sounding needle. At this point,the sounding needle may be removed. The cannula has an inner center thatis removed after insertion, leaving a hard plastic conduit thatfunctions as a catheter. Others with ordinary skill in the art willappreciate other cannula designs may be used in the practice of thisinvention.

An exemplary sounding needle 110 and cannula 112 are illustrated in FIG.1D.

A pull wire assembly 120 is then inserted through a passage formedwithin the cannula. The pull wire includes a mating end 122 and a pullend 124. The mating end is inserted into the cannula. The mating end 122includes structure for providing a means to be grabbed by a snare. Themating end has no sharp edges or parts that may snag within the body. Asillustrated, the structure is a loop, although other structure may beused in the practice & the present invention.

The surgeon now uses the snare assembly previously discussed. The snareassembly includes a snare 130, a snare operating device 132, and a cable134 connecting the snare to the snare operating device. The snare ismanipulated around the pull wire mating end. After the pull wire issecured by the snare, the internal magnet is decoupled from the externalmagnet by manually removing the external magnet from the abdominal wall.Gravity then acts upon the internal magnet causing it to fall away fromthe lumen.

The pull wire is pulled out of the gastrointestinal tract, up theesophagus, until the mating end is visible adjacent the subject's mouth.It is important that the pull end remained disposed outside theabdominal wall.

A feeding tube assembly is utilized by attaching a feeding tube assemblyto the mating end. An exemplary feeding tube assembly 60 is illustratedin FIG. 6. The feeding tube assembly 60 includes a tube 62 having afirst end 63 and a second end 64, a snare 65, a connector 67 fixedlyjoining the first end 63 to the snare 65, and a dome 68 fixed to thetube second end 64. The snare 65 is attached to the pull wire matingend.

After attachment, the pull wire is used to install complete theinstallation of the feeding tube. By pulling of the pull end of thepulling tube, the dome is moved to within the intestines until, the domeabuts the gastrointestinal wall.

While a single embodiment of the invention has been illustrated anddescribed in considerable detail, the present invention is not to beconsidered limited to the precise construction disclosed. Variousadaptations, modifications and uses of the invention may occur to thoseskilled in the arts to which the invention relates. It is the intentionto cover all such adaptations, modifications and uses falling within thescope or spirit of the annexed claims.

1. A luminal coupling system for providing access directly to a lumenwithin a subject, for use with an endoscope having an instrument passageand an illumination source on a distal end, the system comprising: a. aninternal magnet assembly for inserting into an endoscope instrumentchannel, said internal magnet assembly comprising: i. an internal magnetcomprising a first coupling surface defining a surface shape and size,wherein said internal magnet is characterized by a polar orientation anda magnetic strength; and ii. a tether comprising a first end portionfixed to said magnet, a second end portion disposed remote from saidfirst end portion, and a middle portion spaced between said first andsecond end portions, said middle portion for traversing the endoscopeinstrument channel; b. a snare assembly comprising a first snare, asnare operating device, and a cable connecting said first snare to saidsnare operating device; c. an external magnet comprising a secondcoupling surface defining a surface shape and size, wherein saidexternal magnet is characterized by a polar orientation and a magneticstrength, wherein said polar orientation of said external magnet isopposite said polar orientation of said internal magnet such that saidfirst and said second coupling surfaces are magnetically attracted toeach other; d. a pull wire system comprising a sounding needle, acannula and a pull wire, wherein said pull wire comprises a mating endand a pull end; and e. a feeding tube assembly comprising a tube havinga first end and a second end, a second snare, a connector fixedlyjoining said tube first end to said second snare, and a dome fixed tosaid tube second end.
 2. The device claimed in claim 1 wherein said domecomprises a bottom surface having a tube mounting hole and anannular-shaped perforated side surface, said perforated side surface fordistributing liquid in a plurality of radial directions.
 3. The deviceclaimed in claim 1 wherein said magnetic strength of said internalmagnet and said magnetic strength of said external magnet arecollectively sufficient to magnetically couple said internal andexternal magnets when juxtaposed of either side of an lumen wall.
 4. Thedevice claimed in claim 1 wherein said magnetic strength of saidinternal magnet and said magnetic strength of said external magnet areof collectively sufficient strength to stabilize an intestinal lumen toan abdominal wall when said magnets are juxtaposed of either side of anabdominal wall.
 5. The device claimed in claim 1 wherein said surfaceshape and size of said first coupling surface and said surface shape andsize of said second coupling surface are essentially the same.
 6. Thedevice claimed in claim 1 wherein said external magnet comprisesstructure defining a needle insertion zone.
 7. The device claimed inclaim 1 wherein said internal magnet comprises structure defining aneedle acceptance zone.
 8. The device claimed in claim 1 wherein saidexternal magnet comprises structure defining a needle insertion zone,and said internal magnet comprises structure defining a needleacceptance zone, whereby said needle insertion zone and said needleacceptance zone cooperatively align when said external magnet and saidinternal magnet are magnetically coupled.
 9. The device claimed in claim1 wherein said internal magnet assembly comprises a lock for prohibitingsaid magnet from moving relative to a distal end of an endoscope whenthe internal magnet assembly is inserted into the instrument channel.10. The device in claim 1 wherein said internal magnet comprises acoating of biocompatible material.
 11. The device in claim 1 whereinsaid external magnet comprises a sleeve, said sleeve being disposable toprotect the magnet during initial use and allow for subsequent use ofsaid external magnet.
 12. The device in claim 1 wherein said internalmagnet is constructed of Neodymium Iron Boron (NdFeB).
 13. The device inclaim 1 wherein said external magnet is constructed of Neodymium IronBoron (NdFeB).
 14. The device in claim 1 wherein said external magnetcomprises an assembly of similarly sized and shaped magnets, wherein amagnetic strength of said assembly can be varied by adding or deletingmagnets to the assembly.
 15. The device in claim 1 wherein a width ofsaid external magnet is not greater than 1 inch.
 16. The device in claim1 wherein a width of said internal magnet is not greater than 1 inch.